JP5845847B2 - Negative pressure booster - Google Patents

Description

  The present invention relates to a negative pressure booster applied to an automobile, and in particular, an input is caused by a differential pressure generated between a front negative pressure chamber and a rear transformer chamber defined by a movable partition wall in a housing. The present invention relates to a negative pressure booster configured to be increased and output.

  As one of the negative pressure type boosters of this type, a valve body connected to a movable partition that divides the inside of a housing into a front negative pressure chamber and a rear variable pressure chamber is provided with a shaft hole. Includes a plunger that can move forward and backward in the axial direction with respect to the valve body and moves integrally with the input member, and communicates between the negative pressure chamber and the variable pressure chamber according to the forward and backward movement of the plunger with respect to the valve body. A reaction mechanism that incorporates a negative pressure valve that shuts off and a valve mechanism that includes an atmospheric valve that communicates and shuts off the variable pressure chamber and the atmosphere, and a front end portion of the plunger and a front end portion of the valve body that can engage with a rear surface; An output member that is engaged with the front surface of the reaction member at the rear end portion and is movable in the axial direction with respect to the valve body is assembled, and the atmospheric valve is provided at the rear end portion of the plunger. Tapered large And the valve seat, have their air valve portion of the seated-lifted away possible arranged annular to this atmosphere valve seat, for example, described in Patent Document 1 below.

JP 7-291119 A

  In the negative pressure type booster described in Patent Document 1 described above, a cylindrical silencing member is assembled in the cylindrical valve body of the valve mechanism assembled in the shaft hole of the valve body on the outer periphery of the plunger. The cylindrical silencing member is configured to move integrally with the cylindrical valve body of the valve mechanism and move relative to the outer periphery of the plunger. For this reason, the cylindrical sound deadening member is limited in use to a tandem valve having a cylindrical valve body, and is structurally arranged to fill the entire air flow path area. Occurs. In addition, the cylindrical sound deadening member may be sandwiched between the valve seat (second valve seat) and the plunger to cause an airtight leak. If an annular gap is formed between the silencer and the outer periphery of the plunger so that the silencer does not slide on the plunger in the above-described configuration, the atmosphere (air) that flows along the valve seat of the plunger However, it flows through the annular gap between the silencer member and the plunger, and it becomes difficult to pass through the interior of the silencer member, so that the silencer member does not function effectively.

The present invention has been made to solve the above-described problems, and in the above-described negative pressure type booster, when the air flowing along the atmospheric valve seat is separated (separated) from the atmospheric valve seat. rectifying member for absorbing the turbulence with high energy, at the front of the air valve seat, have integrally assembled to the outer periphery of the plunger, the front end portion of the tapered atmosphere valve seat peeling The rectifying member is formed in a cylindrical shape, and the outer periphery of the rectifying member is formed in a tapered shape with a small diameter at the front, excluding the rear end portion. This is characterized by a negative pressure booster characterized by In this case, the rectifying member is preferably formed of an open-celled porous material having sound absorbing properties and air permeability.

  In the negative pressure type booster according to the present invention, when the atmospheric valve opens, the variable pressure chamber communicates with the atmosphere, and when the atmosphere (air) flows into the variable pressure chamber through the atmospheric valve, the air separated from the atmospheric valve seat is separated. Immediately after that, the current can be rectified by the rectifying member, and the turbulent energy generated at the site immediately after the separation can be absorbed. Therefore, the generation of turbulent flow at the site immediately after separation is suppressed, and the delay in the operation response and the operation noise due to the turbulent flow are suppressed. Further, the rectifying member only needs to be in contact with the peeling portion (maximum diameter portion) at the front end portion of the tapered atmospheric valve seat, and since the flow path is not narrowed unnecessarily, it is difficult to cause air flow resistance. There is almost no loss of responsiveness. Furthermore, since the rectifying member is integrally assembled on the outer periphery of the plunger in front of the atmospheric valve seat, there is no possibility of being sandwiched between the atmospheric valve seat (plunger) and the atmospheric valve portion.

In the present invention, the rectifying member is formed in a cylindrical shape, and the outer periphery of the rectifying member is formed in a tapered shape having a small diameter on the front side except for the rear end portion . Therefore , since the flow passage area of the passage formed on the outer periphery of the rectifying member gradually increases and changes toward the variable pressure chamber, it is possible to suppress a rapid volume increase change of the atmosphere entering the variable pressure chamber. The generation of turbulent flow associated with a sudden change in volume of the atmosphere can be suppressed. For this reason, the generation | occurrence | production of the operation | movement response delay and operation sound resulting from a turbulent flow is further suppressed.

Further, according to the present invention , in front of the atmospheric valve seat of the plunger, a cylindrical portion to which the inner periphery of the rear end portion of the rectifying member is assembled is continuous with the same diameter with respect to the large diameter portion of the atmospheric valve seat. It can also be implemented by being formed. In this case, the cylindrical portion is continuously formed with the same diameter with respect to the large-diameter portion of the atmospheric valve seat in front of the atmospheric valve seat, so that even if the axial dimension of the cylindrical portion varies, the atmospheric valve The outer dimension of the seat can be formed with high accuracy, and the atmospheric valve seat can be formed easily and accurately. Further, in this case, since the radially outer end of the atmospheric valve seat does not have a sharp shape, it is not necessary to perform special management for preventing the outer peripheral portion from being damaged or dented.

In the present invention , a cylindrical portion having the same diameter as the large-diameter portion of the atmospheric valve seat is formed in front of the atmospheric valve seat of the plunger. It can also be implemented by attaching the flow straightening member formed in an annular shape to the annular groove formed in the outer periphery of the rear end portion. In this case, the flow regulating member can be reduced in size and cost.

It is sectional drawing which shows 1st Embodiment of the negative pressure type booster by this invention. It is a principal part expanded sectional view of the negative pressure type booster shown in FIG. 1 (sectional drawing in ABC of the valve body shown in FIG. 3). FIG. 3 is a rear view of the single valve body shown in FIGS. 1 and 2. It is a principal part expanded sectional view which shows 2nd Embodiment of the negative pressure type booster by this invention. It is a principal part expanded sectional view which shows 3rd Embodiment of the negative pressure type booster by this invention. It is a principal part expanded sectional view which shows 4th Embodiment of the negative pressure type booster by this invention. It is a principal part expanded sectional view which shows 5th Embodiment of the negative pressure type booster by this invention.

  Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 show a first embodiment in which the present invention is implemented in a negative pressure booster for a vehicle brake. In the negative pressure booster according to the first embodiment, a housing 10 has a movable partition 21. The power piston 20 including the valve body 22 is assembled, and the housing 10 is partitioned by a movable partition wall 21 into a front negative pressure chamber R1 and a rear variable pressure chamber R2.

  As shown in FIG. 1, the housing 10 includes a front shell 11 and a rear shell 12, and a negative pressure for constantly communicating the negative pressure chamber R1 with a negative pressure source (for example, an intake manifold of an engine not shown). An introduction pipe 13 is provided. The housing 10 is a stationary member by a screw portion 14a provided at the rear end portion of a plurality of tie rods 14 (one is shown in FIG. 1) penetrating the housing 10 and the movable partition wall 21 in an airtight manner. That is, it is configured to be fixed to a vehicle body (not shown). Note that the brake master cylinder 100 is assembled to the screw portion 14b provided at the front end portion of the tie rod 14.

  The brake master cylinder 100 has a rear end portion 101a of the cylinder body 101 penetrating through a central cylinder portion 11a formed in the front shell 11 and hermetically entering the negative pressure chamber R1, and is formed in the cylinder body 101. The rear surface of the flange portion 101 b is in contact with the front surface of the front shell 11. The piston 102 of the brake master cylinder 100 protrudes rearward from the cylinder body 101 and enters the negative pressure chamber R1, and is configured to be pushed forward by a distal end rod portion 35a of the output shaft 35 described later. Has been.

  The movable partition wall 21 of the power piston 20 includes a metal-made annular plate 21a and a rubber-made annular diaphragm 21b, and is installed in the housing 10 so as to be movable in the front-rear direction (the axial direction of the power piston 20). ing. The diaphragm 21b is airtightly sandwiched between the folded portion provided at the outer peripheral edge of the rear shell 12 and the front shell 11 at an annular outer peripheral bead portion formed at the outer peripheral edge thereof. The diaphragm 21b is hermetically fixed together with the inner peripheral portion of the plate 21a in an annular groove formed on the outer periphery of the front end portion of the valve body 22 at an annular inner peripheral bead portion formed on the inner peripheral edge thereof. .

  The valve body 22 of the power piston 20 is a resin hollow body connected to the inner peripheral portion of the movable partition wall 21, and is airtight and front-rear to the rear shell 12 of the housing 10 at an intermediate portion formed in a cylindrical shape. It is assembled so as to be movable in the direction, and is urged rearward by a return spring 15 interposed between the housing 10 and the front shell 11. The portion of the valve body 22 that protrudes outside the housing 10 is covered and protected by a boot 19 having a plurality of vent holes 19a at the rear end.

  Further, as shown in FIGS. 2 and 3, the valve body 22 is formed with a stepped shaft hole 22a penetrating in the front-rear direction, and at the rear end of the intermediate step portion of the shaft hole 22a. A pair of negative pressure communication passages 22b (only one is shown in FIGS. 1 and 2) communicating with the negative pressure chamber R1 at the front end and a key member substantially orthogonal to the front portion of the shaft hole 22a A pair of key attachment holes 22c (only one of which is shown in FIGS. 1 and 2) through which 39 can be inserted from the outer periphery are formed.

  The input shaft 31 and the plunger 32 are coaxially assembled in the shaft hole 22a, and the valve mechanism V and the filters 51 and 52 are coaxially assembled. In addition, a reaction member 34 and an output shaft (output member) 35 are coaxially assembled in front of the plunger 32 in the shaft hole 22a.

  The input shaft 31 can be moved back and forth with respect to the valve body 22, is connected to the receiving connection portion 32c of the plunger 32 in a joint shape by a spherical tip portion 31a, and the brake pedal via a yoke at the rear end screw portion 31b. (Both are not shown) and is configured to receive a pedal force acting on the brake pedal as an input.

  The plunger 32 can be engaged with the central portion of the rear surface of the reaction member 34 at the tip end portion 32a, and can be engaged with the key member 39 at the annular flange portion 32b formed at the intermediate portion thereof. The portion 32 a is a portion that partially receives the reaction force of the output from the reaction member 34. An annular atmospheric valve seat 32d is formed at the rear end of the plunger 32 so as to be separable from the annular atmospheric valve portion 41b of the valve mechanism V, and the annular atmosphere of the atmospheric valve seat 32d and the valve mechanism V is formed. The valve portion 41b constitutes an atmospheric valve that communicates and blocks between the variable pressure chamber R2 and the atmosphere.

  The reaction member 34 is a reaction rubber disk whose rear surface has a central portion that can bulge and deform rearwardly. The reaction member 34 is accommodated in the rear cylindrical portion 35b of the output shaft 35 and is located on the rear surface of the rear end portion of the output shaft 35 over the entire front surface. In an engaged (abutted) state, the valve body 22 is assembled to the front end portion. The reaction member 34 can contact the front surface of the distal end portion 32 a of the plunger 32 at the rear surface thereof, and also contact the annular front end surface of the valve body 22.

  The output shaft 35 is assembled in the front end portion of the shaft hole 22a of the valve body 22 together with the reaction member 34 so as to be movable in the front-rear direction, and as shown in FIG. 1, the distal end rod portion 35a assembled to the distal end portion. Is in contact with the engaging portion of the piston 102 in the brake master cylinder 100 so as to be able to be pushed, and the reaction force received from the piston 102 of the brake master cylinder 100 is transmitted to the reaction member 34 during braking operation.

  The key member 39 defines the function of defining the movement of the plunger 32 in the front-rear direction with respect to the valve body 22 of the power piston 20 and the limit position of the rearward movement of the power piston 20 with respect to the housing 10 (rear return position of the valve body 22). It has a function and is assembled to the valve body 22 and the plunger 32 so as to be movable relative to each other in the axial direction of the power piston 20.

  The valve mechanism V includes an arc-shaped negative pressure valve seat 22d integrally formed at the rear end portion of each negative pressure communication passage 22b in the valve body 22, and an annular atmospheric valve seat formed integrally at the rear end portion of the plunger 32. 32d and a cylindrical valve body 41 that is coaxially disposed with respect to the atmospheric valve seat 32d and is assembled to the valve body 22. The valve body 41 has a negative pressure valve portion 41a that constitutes a negative pressure valve that can be seated / separated with respect to the negative pressure valve seat 22d and that can communicate and block the negative pressure chamber R1 and the variable pressure chamber R2 by the negative pressure valve seat 22d. At the same time, the atmospheric valve seat 32d has an annular atmospheric valve portion 41b that constitutes an atmospheric valve that can be seated and separated from the atmospheric valve seat 32d and that can communicate with and shut off the atmosphere from the variable pressure chamber R2.

  The negative pressure valve portion 41a and the atmospheric valve portion 41b are formed integrally with a movable portion (a portion movable in the axial direction) of the valve body 41, and are directed toward the negative pressure valve seat 22d and the atmospheric valve seat 32d by the compression spring 42. Is energized (towards the front). The fixed portion (portion that cannot move in the axial direction) of the valve body 41 is urged forward by a compression spring 44 that is engaged with the stepped portion of the input shaft 31 via the retainer 43, so that the valve body 22 is held at a fixed position (step portion) of the shaft hole 22a.

  With the configuration of the valve mechanism V described above, the variable pressure chamber R2 can communicate with the negative pressure chamber R1 or the atmosphere in accordance with the movement of the input shaft 31 and the plunger 32 in the front-rear direction with respect to the valve body 22. That is, the input shaft 31 and the plunger 32 shown in FIGS. 1 and 2 move forward from the original position with respect to the valve body 22, the negative pressure valve portion 41a is seated on the negative pressure valve seat 22d, and the atmospheric valve seat 32d is When separated from the atmospheric valve portion 41b, the variable pressure chamber R2 is disconnected from the negative pressure chamber R1 and communicates with the atmosphere. At this time, the vent hole 19a of the boot 19, the filters 51 and 52, the inside of the valve body 41, the gap between the atmospheric valve seat 32d and the atmospheric valve portion 41b, the axial communication path X and the radial communication path provided in the valve body 22. Air flows into the variable pressure chamber R2 through Y and the like.

  Further, as shown in FIGS. 1 and 2, the input shaft 31 and the plunger 32 return to the return position (original position) with respect to the valve body 22, and the atmospheric valve seat 32d is seated on the atmospheric valve portion 41b and is negative. A state in which the pressure valve portion 41a is separated from the negative pressure valve seat 22d (that is, the atmospheric valve is closed, the communication between the variable pressure chamber R2 and the atmosphere is shut off, and the negative pressure valve is opened, so that the negative pressure chamber R1 In the state in which the chamber R2 communicates), the variable pressure chamber R2 is disconnected from the atmosphere and communicates with the negative pressure chamber R1. At this time, from the variable pressure chamber R2 to the negative pressure chamber R1 through the radial communication passage Y and the axial communication passage X provided in the valve body 22, the gap between the negative pressure valve portion 41a and the negative pressure valve seat 22d, the negative pressure communication passage 22b, and the like. Air is sucked and flows.

  As shown in FIG. 2, the axial communication passage X described above is provided in the rear axial communication passage X1 formed on the outer periphery of the rear portion of the plunger 32 in front of the atmospheric valve, and in the valve body 22, and the rear. It is formed by the front axial communication path X2 communicating with the rear axial communication path X1 at the end. On the other hand, as shown in FIG. 2, the above-described radial communication path Y is provided in the valve body 22 at a portion where each negative pressure communication path 22b is not formed, and the variable pressure chamber R2 at the outer diameter end. And communicates with the forward axial communication path X2 in the radially inward direction.

  By the way, in this 1st Embodiment, as shown in FIG.2 and FIG.3, the cylindrical rectification | straightening member 61 is integrally assembled | attached to the outer periphery of the plunger 32. As shown in FIG. The rectifying member 61 is formed of an open-celled porous material (for example, rubber sponge) having sound absorption and breathability, and a valve is formed in front of a tapered atmospheric valve seat 32d having a large diameter in the front. The body 22 is assembled in a non-contact state with respect to the shaft hole inner wall S of the body 22 (the shaft hole inner wall at the portion where the negative pressure communication path 22b is formed).

  The rectifying member 61 absorbs turbulent flow having high energy when the air flowing along the atmospheric valve seat 32d is separated (separated) from the atmospheric valve seat 32d (along the atmospheric valve seat 32d). The air (atmosphere) that flows and is separated from the atmospheric valve seat 32d is rectified immediately after the separation to absorb turbulent energy that generates turbulent flow), and its outer diameter is the maximum diameter of the atmospheric valve seat 32d. It is formed larger than the predetermined amount, and is in contact with the peeling portion (maximum diameter portion) at the front end of the tapered atmospheric valve seat 32d. Note that the front end of the rectifying member 61 is in contact with the rear surface of the cylindrical portion 22e of the valve body 22 (portion supporting the intermediate portion in the axial direction of the plunger 32), and the plunger 32 is moved from the original position (return position). When moving forward in the axial direction, it is configured to be deformed almost without resistance in the axial direction.

  In the negative pressure booster of the first embodiment configured as described above, the brake pedal is depressed to advance the input shaft 31 and the plunger 32 from the original position (return position) to the axial direction with respect to the valve body 22. When moved, the negative pressure valve portion 41a is seated on the negative pressure valve seat 22d, the negative pressure valve is closed, the communication between the negative pressure chamber R1 and the variable pressure chamber R2 is blocked, and the atmospheric valve seat 32d is replaced with the atmospheric valve portion 41b. The atmospheric valve is opened by separating from the open space, and the variable pressure chamber R2 communicates with the atmosphere. For this reason, the atmosphere flows into the variable pressure chamber R2 through the open atmospheric valve, the axial communication passage X, and the radial communication passage Y, and the pressure in the variable pressure chamber R2 gradually changes from negative pressure to atmospheric pressure. An output corresponding to the differential pressure between the variable pressure chambers R <b> 2 is generated on the output shaft 35. When an output is generated on the output shaft 35, the reaction force is transmitted from the output shaft 35 to the front surface 34 a of the reaction member 34, and transmitted from the rear surface of the reaction member 34 to the valve body 22 and the plunger 32.

  By the way, in the negative pressure type booster of the first embodiment, when the air flowing along the atmospheric valve seat 32d is separated (separated) from the atmospheric valve seat 32d, turbulent flow having high energy is absorbed. The rectifying member 61 is integrally assembled with the outer periphery of the plunger 32 in front of the atmospheric valve seat 32d, and abuts against the peeling portion (maximum diameter portion) at the front end of the tapered atmospheric valve seat 32d. ing. For this reason, when the atmospheric valve opens, the variable pressure chamber R2 communicates with the atmosphere, and when the atmosphere (air) flows into the variable pressure chamber R2 through the atmospheric valve, the air that is separated from the atmospheric valve seat 32d is immediately after the rectifying member 61. Can rectify and absorb the turbulent energy generated at the site immediately after peeling. Therefore, the generation of turbulent flow at the site immediately after separation is suppressed, and the delay in the operation response and the operation noise due to the turbulent flow are suppressed.

  Moreover, in this 1st Embodiment, the rectification | straightening member 61 should just contact | abut to the peeling part (maximum diameter part) in the front-end part of the taper-shaped atmospheric valve seat 32d, and can narrow a flow path unnecessarily. Therefore, the resistance to air flow hardly occurs and the responsiveness is hardly impaired. Furthermore, since the rectifying member 61 is integrally assembled to the outer periphery of the plunger 32 in front of the atmospheric valve seat 32d, there is no possibility of being sandwiched between the atmospheric valve seat (plunger) 32d and the atmospheric valve portion 41d. Further, the flow regulating member 61 is integrally assembled on the outer periphery of the plunger 32 in a non-contact state with respect to the inner wall S of the valve body 22 and moves integrally with the plunger 32. For this reason, when the plunger 32 moves, the rectifying member 61 does not slidably contact the shaft hole inner wall S of the valve body 22, and the operation response delay due to the slidable contact between the shaft hole inner wall S of the valve body 22 and the rectifying member 61 also occurs. Does not occur. Moreover, in this 1st Embodiment, since the rectification | straightening member 61 is formed with the porous material of an open cell, the outstanding sound absorption property and air permeability are obtained.

  In the first embodiment described above, the rectifying member 61 is formed in a cylindrical shape and the outer diameter thereof is the same over the entire length. However, as in the second embodiment shown in FIG. The outer diameter of the rectifying member 61 formed in the shape may be configured to be formed in a tapered shape with a small diameter at the front, excluding the rear end portion. In the second embodiment, the flow passage area of the passage (rear axial communication passage X1) formed on the outer periphery of the rectifying member 61 gradually increases and changes toward the variable pressure chamber R2, so that the atmosphere entering the variable pressure chamber R2 Can be suppressed, and the generation of turbulent flow accompanying the rapid volume increase of the atmosphere in the variable pressure chamber R2 can be suppressed. For this reason, the generation | occurrence | production of the operation | movement response delay and operation sound resulting from a turbulent flow is further suppressed compared with the said 1st Embodiment.

  In the first embodiment and the second embodiment described above, the rear end surface of the rectifying member 61 extending radially outward perpendicular to the axis L at the large-diameter portion of the atmospheric valve seat 32d in the plunger 32, and the plunger 32 The rear end surface of the rectifying member 61 extending radially inwardly perpendicular to the axis L at the large-diameter portion of the atmospheric valve seat 32d is configured to be the same surface, but the third embodiment shown in FIG. Alternatively, as in the fourth embodiment shown in FIG. 6, a cylindrical portion 32 e to which the inner periphery of the rear end of the rectifying member 61 is assembled in front of the atmospheric valve seat 32 d of the plunger 32 is a large diameter portion of the atmospheric valve seat. On the other hand, it is also possible to configure and implement such that they are continuously formed with the same diameter. In the third embodiment and the fourth embodiment, the plunger 32 is formed with the cylindrical portion 32e, and the recess 61a is formed on the inner periphery of the rear end portion of the rectifying member 61 according to this. Except for, the configuration is the same as that of the first embodiment and the second embodiment described above.

  In the third and fourth embodiments, the cylindrical portion 32e is continuously formed with the same diameter with respect to the large-diameter portion of the atmospheric valve seat 32d in front of the atmospheric valve seat 32d, so that the cylindrical portion 32e. Even if there are variations in the axial dimension, the outer dimension of the atmospheric valve seat 32d can be formed with high accuracy, and the atmospheric valve seat 32d can be formed easily and accurately. Further, in the third and fourth embodiments, since the radially outer end of the atmospheric valve seat 32d does not have a sharp shape, it is necessary to perform special management for preventing the outer peripheral portion from being damaged or dented. There is no.

  In the first to fourth embodiments described above, when the front end of the rectifying member 61 is in contact with the rear surface of the cylindrical portion 22e of the valve body 22, and the plunger 32 moves forward in the axial direction from the original position (return position). The rectifying member 61 is configured to be deformed in the axial direction. However, as in the fifth embodiment shown in FIG. 7, the large diameter of the atmospheric valve seat 32d is provided in front of the atmospheric valve seat 32d of the plunger 32. A cylindrical portion 32e having the same diameter as the portion is formed continuously with the atmospheric valve seat 32d, and a rectifying member 61 formed in an annular shape is formed in an annular groove 32e1 formed in the outer periphery of the rear end portion of the cylindrical portion 32e. It is also possible to configure and implement so as to be assembled. In the fifth embodiment, the rectifying member 61 formed in an annular shape provides the same operation and effect as the rectifying member 61 of the first embodiment described above, and the rectifying member 61 is reduced in size and cost. Is possible.

DESCRIPTION OF SYMBOLS 10 ... Housing, 20 ... Power piston, 21 ... Movable partition, 22 ... Valve body, 22a ... Shaft hole, 22b ... Negative pressure communication path, 22c ... Key attachment hole, 22d ... Negative pressure valve seat, 22e ... Cylindrical part, S ... Valve Body shaft hole inner wall step, 31 ... input shaft, 32 ... plunger, 32d ... atmospheric valve seat, 32e ... cylindrical part, 34 ... reaction member, 35 ... output shaft, 39 ... key member, 41 ... valve element, 41a ... negative Pressure valve portion, 41b ... Atmospheric valve portion, X ... Axial communication passage, X1 ... Rear axial communication passage, X2 ... Front axial communication passage, Y ... Radial communication passage, V ... Valve mechanism, R1 ... Negative pressure Room, R2 ... Transformer room

Claims (4)

A valve body connected to a movable partition that divides the inside of the housing into a front negative pressure chamber and a rear variable pressure chamber has a shaft hole, and the shaft body advances and retreats in the axial direction with respect to the valve body. A plunger that can move integrally with the input member, a negative pressure valve that communicates and shuts off the negative pressure chamber and the variable pressure chamber and communicates between the variable pressure chamber and the atmosphere as the plunger moves forward and backward relative to the valve body. A reaction mechanism in which a valve mechanism having a shut-off atmospheric valve is incorporated, a front end portion of the plunger and a front end portion of the valve body can be engaged with a rear surface, and a front end of the reaction member at a rear end portion An output member that is movable in the axial direction with respect to the valve body is assembled, and the atmospheric valve includes a tapered atmospheric valve seat provided at a rear end portion of the plunger, and the atmospheric valve seat. Sitting against In the vacuum booster which is equipped with an atmospheric valve portion of the seat can be arranged annular,
When the air flowing along the atmospheric valve seat is separated from the atmospheric valve seat, a rectifying member that absorbs turbulent flow having high energy is integrated with the outer periphery of the plunger in front of the atmospheric valve seat. have assembled to, the the peeling section at the front end of the tapered atmospheric valve seat abuts, and the rectifying member is formed into a cylindrical shape, the outer circumference of the rectifying member after A negative pressure type booster characterized by being formed in a tapered shape with a small diameter at the front, excluding the end . A valve body connected to a movable partition that divides the inside of the housing into a front negative pressure chamber and a rear variable pressure chamber has a shaft hole, and the shaft body advances and retreats in the axial direction with respect to the valve body. A plunger that can move integrally with the input member, a negative pressure valve that communicates and shuts off the negative pressure chamber and the variable pressure chamber and communicates between the variable pressure chamber and the atmosphere as the plunger moves forward and backward relative to the valve body. A reaction mechanism in which a valve mechanism having a shut-off atmospheric valve is incorporated, a front end portion of the plunger and a front end portion of the valve body can be engaged with a rear surface, and a front end of the reaction member at a rear end portion An output member that is movable in the axial direction with respect to the valve body is assembled, and the atmospheric valve includes a tapered atmospheric valve seat provided at a rear end portion of the plunger, and the atmospheric valve seat. Sitting against In the vacuum booster which is equipped with an atmospheric valve portion of the seat can be arranged annular,
When the air flowing along the atmospheric valve seat is separated from the atmospheric valve seat, a rectifying member that absorbs turbulent flow having high energy is integrated with the outer periphery of the plunger in front of the atmospheric valve seat. have been assembled, said has a release portion at the front end of the tapered atmospheric valve seat abuts, and, in front of the air valve seat of the plunger, the rear end portion inner periphery of the rectifying member The negative pressure type booster is characterized in that the cylindrical portion to which the is attached is continuously formed with the same diameter with respect to the large diameter portion of the atmospheric valve seat . A valve body connected to a movable partition that divides the inside of the housing into a front negative pressure chamber and a rear variable pressure chamber has a shaft hole, and the shaft body advances and retreats in the axial direction with respect to the valve body. A plunger that can move integrally with the input member, a negative pressure valve that communicates and shuts off the negative pressure chamber and the variable pressure chamber and communicates between the variable pressure chamber and the atmosphere as the plunger moves forward and backward relative to the valve body. A reaction mechanism in which a valve mechanism having a shut-off atmospheric valve is incorporated, a front end portion of the plunger and a front end portion of the valve body can be engaged with a rear surface, and a front end of the reaction member at a rear end portion An output member that is movable in the axial direction with respect to the valve body is assembled, and the atmospheric valve includes a tapered atmospheric valve seat provided at a rear end portion of the plunger, and the atmospheric valve seat. Sitting against In the vacuum booster which is equipped with an atmospheric valve portion of the seat can be arranged annular,
When the air flowing along the atmospheric valve seat is separated from the atmospheric valve seat, a rectifying member that absorbs turbulent flow having high energy is integrated with the outer periphery of the plunger in front of the atmospheric valve seat. have been assembled, said has a release portion at the front end of the tapered atmospheric valve seat abuts, and, in front of the air valve seat of the plunger, the large diameter portion of the atmosphere valve seat Is formed continuously with the atmospheric valve seat, and the annular groove formed in the outer periphery of the rear end portion of the cylindrical portion is assembled with the rectifying member formed in an annular shape. A negative pressure booster characterized by comprising: The negative pressure type booster according to any one of claims 1 to 3, wherein the rectifying member is formed of an open-cell porous material having sound absorption and air permeability. Pressure booster.

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